mirror/guile
mirror/guile
1
Fork 0
mirror of https://git.savannah.gnu.org/git/guile.git synced 2025-05-01 04:10:18 +02:00
Code Activity

NULLSTACK fixes for nonlocal exits in reentrant pre-wind handlers

Browse source 
* libguile/vm-i-system.c (goto/cc): Add some asserts here.

* libguile/vm.c (capture_vm_cont): Add some asserts here too.
  (reinstate_vm_cont): Null the correct number of bytes. Add a FIXME.
  (vm_reset_stack): Make the code a bit clearer. Null the correct number
  of bytes.

* libguile/vm-engine.h (NULLSTACK_FOR_NONLOCAL_EXIT): New macro, handles
  a very tricky case that took me days to find! Amply commented. Expands
  to nothing in the normal case.

* libguile/vm-i-system.c (call, goto/args, mv-call): Call
  NULLSTACK_FOR_NONLOCAL_EXIT in the right places. Fixes
  continuations.test.
This commit is contained in:
Andy Wingo 2008-10-09 14:44:43 +02:00
parent 0570c3f197
commit 66db076ae1
3 changed files with 24 additions and 5 deletions
Download patch file Download diff file Expand all files Collapse all files

7
libguile/vm-engine.h
View file

@ -247,10 +247,17 @@
# define CHECK_STACK_LEAKN(_n) ASSERT (!sp[_n]);
# define CHECK_STACK_LEAK() CHECK_STACK_LEAKN(1)
# define NULLSTACK(_n) { int __x = _n; CHECK_STACK_LEAKN (_n+1); while (__x > 0) sp[__x--] = NULL; }
/* If you have a nonlocal exit in a pre-wind proc while invoking a continuation
inside a dynwind (phew!), the stack is fully rewound but vm_reset_stack for
that continuation doesn't have a chance to run. It's not important on a
semantic level, but it does mess up our stack nulling -- so this macro is to
fix that. */
# define NULLSTACK_FOR_NONLOCAL_EXIT() if (vp->sp > sp) NULLSTACK (vp->sp - sp);
#else
# define CHECK_STACK_LEAKN(_n)
# define CHECK_STACK_LEAK()
# define NULLSTACK(_n)
# define NULLSTACK_FOR_NONLOCAL_EXIT()
#endif
#define CHECK_OVERFLOW() \